The present teachings relate to a neutron detector and a fabrication method thereof. More particularly, the present teachings relate to a neutron detector comprising a solid state sensing material and a fabrication method thereof.
Various characteristics of nuclear materials need to be tested and studied before use. Such nuclear materials include an accountable nuclear material, which is a collective term that encompasses all materials designated in quantities that require special control. Examples of these materials include plutonium, enriched uranium, americium, and depleted uranium. Effective capabilities to detect, deter, and assist in the prevention of theft or diversions of accountable nuclear materials are, therefore, critical. As such, control of and accountability for these materials are provided through, for example, the Material Control and Accountability (MC&A) program of the Department of Energy (DOE).
Implementation of nuclear Material Control and Accountability MC&A programs requires techniques and equipment that maximize material loss detection sensitivity, increase the accuracy of accountability measurements, minimize material supply disruptions, and reduce the magnitude of inventory differences and associated control limits, consistent with the consequences of the loss, misplacement or inadequate tracking of material. Similarly, new methods and technologies are needed to address key issues affecting future deployments of nuclear-based energy production and of other nuclear materials while reducing the risks already stated. Currently, these tasks often depend upon neutron counters, which typically use moderated thermal neutron detectors. In order to achieve high detection efficiency, thermal neutron detectors filled with 3He gas are commonly used. However, due to the acute ongoing worldwide shortage of 3He, these detectors have become prohibitively expensive. Thus, successfully undertaking of MC&A requires new detectors that effectively eliminate the need for 3He.
Accordingly, there is a need to develop a new detector capable of meeting present and future challenges of low-cost, high neutron detection efficiency, solid-state, and mass-production. Such devices should allow for compact detection system configurations, such as position-sensitive arrays embedded in a moderator, which is not feasible with the larger, 3He gas-filled detectors. Further, such a new device should use materials that are easy to produce, economical, and be able to maintain high thermal neutron detection efficiency and gamma rejection close to the 3He standards.